Technical Field
The present disclosure relates to a touch sensing apparatus.
Discussion of the Related Art
User interfaces (UIs), enabling communication between human beings (users) and various electric or electronic devices, allow users to easily control devices as they like. Typical examples of such user interfaces include keypads, keyboards, mouse, on-screen displays (OSDs), and remote controllers having an infrared or radio frequency (RF) communication function. User interface techniques have steadily advanced toward enhancing user emotions and operation convenience. Recently, user interfaces have evolved into touch UIs, voice recognition UIs, and 3D UIs, and thereamong, the touch UIs tend to be predominantly installed in portable information devices. Applications of touch UIs include a touch sensing apparatuses installed in display devices of home appliances or in portable information devices.
A capacitive touch sensing apparatus has high durability and spatial precision and enables multi-touch recognition and proximity touch recognition. Capacitive touch sensors can be used in various applications, more so than existing resistive touch sensing schemes. In the capacitive touch sensing apparatus, a touch sensor maybe bonded to a display device or maybe installed in a display panel of the display device, and thus, the touch sensor is electrically coupled with the display pixels of the display device.
The touch sensing apparatus determines whether a touch has been applied to the touch sensor upon sensing a change in capacitance of the touch sensor; but in some cases, an amount of a change in capacitance of the touch sensor due to an external touch is so small that it is not easy to determine whether a touch has been applied.
In order to more accurately determine whether a touch has been applied, a longer touch driving period is needed. However, the touch panel coupled to the display panel is driven with the display panel in a time-division multiplexed manner within one frame period, making it difficult to secure a sufficiently long touch screen driving period.